Process for producing pigmentary base products for lead paints



Patented Nov. E9, 3929 airan arenas mat AXEL VIGGQ BLQM, GEGBGSSHOEGHSTETTEN, SWITZERLAND PROCESS FOR PRODUCING- ?IGMENTARY BASEPRODUCTS FOR LEAD PAINTS no Drawing. application filed April 5,

My invention concerns aprocess for producing materials adapted to serveas pigmentary bases for paints and particularly lead paints suitable foruse as rust proof coating for iron and other objects and surfaces. In

my copending application, Serial No. 181,27 8,

filed April 5, 1927, I have described a new and improved material ofthis character and a process suitable for producing the same. In

carrying out the said process, I have found that the oxidation of themetallic lead or lead alloy as carried out in my process is occasionallysomewhat sluggish. l have discovered that this sluggishness can beovercome and the reaction speeded u by the presence of catalyzingsubstances. have also found that it is not necessary to use largequantities of catalyzing substances as compared to the uantity ofmaterial under treatment, but

that even a comparatively small amount of the said catalyzers issufficient to show a decided influence on the speed of the reaction.

As such catalyzin substance I have found that all the salts of calciumwith high molecular organic acids are suitable, for example,

the resinate, naphthenate, and oleate salts,

but I preferably use calcium resinate and l.

have observed that as little as one-half per cent of this substanceafiects appreciably the speeding up of the oxidizing reaction. Indarrying out my invention I proceed in the fol lowing manner.

I take metallic lead or an alloy containing a high percentage of leadsuch as described :15 in my copending application, Serial No.

181,278,- filed April 5, 1927, for instance an alloy containing 85%lead, 13% antimony and 2% tin, and melt the same in a furnace of theusual construction, provided with a flat 4o pan-shaped hearth, in thepresence of per cent of calcium resinate. The interior of the saidfurnace is adapted to be closed airtight,

- so that a certain vacuum can be established therein,

to undergo a slow ox1dat1on process by means I then cause the saidmolten metal 1927. Serial in. 131,279.

the slow oxidation of the molten bath and the formation of a pigmentarybase of the character described in my copending application, mentionedabove.

As the pigmentary body forms on the surface of the molten bath it iscarried a'way by the suction of the air introduced into the furnace. Itis collected in any suitable manner, such for instance in a bag plantsimilar. to those used for the deposition of fine dust.

Having thus described my inventionawhat I claim as new and desire tosecure by Letters Patent is 1. A- continuous process for producing apigmentary base of the character described, which consists in melting alead alloy con taining a large percentage of lead in a thin layer in anair tight furnace in the presence of calcium resinate, establishing avacuum in the said furnace, causing the said molten lead to be actedupon'by a plurality of streams of air drawn into the said furnace by thevacuum, continuously removing the product and separating therefrom allpartic es larger than 50 microns. I 2. A continuous process forproducing a I pigmentarybase of the character described,- which consistsin melting a lead alloy containing a large percentage of lead in a thinlayer in an airtight furnace in the presence of a small percentage ofcalcium resinate, establishing a vacuum in the said furnace, causing thesaid molten lead to be. acted upon by a plurality of streams of airdrawn into the said furnace by the vacuum, continuously removing theproduct and separating therefrom all particles larger than 50 microns.

3. A continuous process for producing a pigmentay base of the characterdescribed,

which consists in melting an alloy composed of per cent lead, 13 percent antimony, and 2 percent tin in the presence of a small percentageof calcium resinate in a thin layer in anair tight furnace, establishinga vacuum in the said furnace, causing the said molten lead to be actedupon by a plurality of streams of air drawn into the said furnace by thevacuum, continuously removing the product and separating therefrom allparticles larger than 50 microns.

In testimony whereof, I have signed my name to this specification thistwenty-third day of February, 1927.

AXEL VIGGO BLOM.

